Sewing machine for making onethread machine seams



2,636,461 SEWING MACHINE FOR MAKING ONE-THREAD MACHINE SEAMS Filed Aprii28, 1948 F. MIKOLAS April 28, 1953 3 Sheets-Sheet 1 INVENTQR FRANZ MIKO5 Br 4'00. AG E NTS April 8, 1953 F. MIKOLAS 2,636,461

SEWING MACHINE FOR MAKING ONE-THREAD MACHINE SEAMS Filed April 28, 19483 Sheets-Sheet 2 JZz'g? 2 INVENTOR F. MIKOLAS April 28, 1953 SEWINGMACHINE FOR MAKING ONE-THREAD MACHINE SEAMS Filed April 28, 1948 3Sheets'-Sheet 3 INVENTOR FRANZ MIK BY AGENTS Patented Apr. 28, 1953UNITED SEWING MACHINE FOR MAKING ONE- THREAD MACHINE SEAMS FranzMikolas, Vienna, Austria Application April 28, 1948, Serial No. 23,840In Austria May 2, 1947 9 Claims. 1

Sewing machines are already known for the oneor two-thread chain-stitch,serving the purpose of producing extensible seams. With the one-threadchain-stitch produced by means of the standard machine needle a quiltingstitch is obtained in the material on the entering side of the needle,and a loop on the exit side. The chain-stitch'seam produced is easilyundone.

A well known machine for the production of one-thread tambourorlock-stitch seams is provided with a hooked needle passing through thematerial from above, and with a thread laying out device, rotatableabout the needle axis below the workpiece, inserting the thread into theneedle hook. With the needle rising out of the material the hookedneedle lifts the loop, and with the feed dog pushing the materialforward, the needle passes through the thread loop, pressed against thematerial by the loop holder. The tambour-(lock-)stitch seam used forornamenting is characterized by chain-stitches on the upper, andquilting-stitches on the lower side of the material.

The chain-stitch kinds mentioned are only extensible to the limitallowed by the thread loop loosely lying on the material. If, however, apreliminary tension is imparted to the thread so that only a very slightinterval forms when pulling apart the two material portions sewntogether, than the seam is not extensible anymore in the longitudinaldirection owing to the junction quilting-stitch and to the chain--stitch tightly drawn.

This invention relates to a sewing machine for making a one-threadmachine seam, which is distinguished by a high degree of extensibilitycompatible with a tight tension of the thread and a high resistanceagainst undoing and'ripping up of the portions of material sewntogether, and which consists-on the entering or stitching-in side of thematerial-of chain stitches and quilting-stitch-like junction stitches,which are connected on the exit side by quilting-stitchlike double seamwebs.

According to the invention, the machine comprises an eye needle, ahooked needle moving synchronously with same and having a hook which,when viewed in the direction of material feed, is open in front andadapted to be covered temporarily by a positively controlled auxiliaryneedle, and a thread transmitter, preferably an oscillating looper, andwhich after both needles have pierced through the material, transmitsthe thread supplied by the eye needle as a loopon to the hooked needle,which during the return,

2 movement of the needle, the subsequent conveying of the material, andthe next stitch of the needle, acts as a loop drawer and loop holder ofthe chain-stitch loop which is to be laid out on the entering, i. e.,the stitching-in side.

The arrangement of the two needles, either one behind the other in thedirection of material feed, with the hooked needle in front, or in aplane which is perpendicular to the direction of material feed, dependson whether the chain stitches and quilting-stitch-like junction stitchesare to interlock, being staggered in the direction of the seam, and tobe connected on the other side of the material by seam webs having thesame direction, or whether said stitches are to lie alongside each otherin rows and to have transverse seam webs.

Whereas in both cases the hook of the hooked needle is directed forwardin the direction of feed, the eye of the eye needle is arranged in thefirst case transversely, in the second case longitudinally with respectto the feed direction.

According to the invention the hooked needle cooperates with a shortauxiliary needle (loop stripper) tightly adhering to the front side ofthe hooked needle, which is driven separately, lagging behind the hookedneedle by an angle of and temporarily covering the opening of the hookedneedle during the exit of the needle, whilst retaining, during the entryof the needle, the thread loop previously stripped ofi.

The drawing discloses embodiments of the invention by way of examples,

Fig. 1 showing the sewing machine head according to the first mode ofexecution by way of a frontal elevation, partially in section with thefront plate removed.

Fig. 2 is a longitudinal section through a part of the sewing machinehead.

Fig. 3 is a section taken on the line III--III of Fig. 2, and

Fig. 4 is a section taken on the line IV--IV of Fig. 2.

Fig. 5 is a view of the eccentric controlling the looper, indicating thephases of the rotation of the eccentric coordinated to the individualmotions of the catcher.

Figs. 6-10 illustrate, with reference to the machine shown in a positionturned throughin regard to Fig. l, the formation of the stitches duringthe sewing process in five phases following one upon the other.

Fig. 11 is a perspective illustration of the stitc formation accordingto the second mode of execution of the machine producing a two-rowjunction seam.

As usual the sewing machine is provided with a head whose main shaft Idrives by means of a crank 2 and a connecting rod 3 (pitman) the block3a of the needle bar t together with the take-up lever 3i.

The needle bar t carries the needle clamp 5 to which-when looking at themachine in the material transporting direction-the hooked needle I isscrewed on in front with the hook forward, whilst behind a standardmachine sewing needle 6 (eye-needle) is equally screwed on but with thethread eye located transversely to the sewing direction.

Only one upper thread is worked, said thread being supplied to theeye-needle 6, as usual, by way of the thread tensioner 30, they take-uplever 3|, the thread guiding eye 32, and an eye in the needle clamp 5.

The thread transmitter 25, lodged in the bottom of the head and formedinto a swinging looper executes equal rotary oscillations up to 360about a vertical axis, located laterally in regard to the axes of thetwo needles 6, I and belowsame. Its shaft 'ournaleol in the bearing 21carries the driving pinion 26 registering with a toothed are 28 tightlyscrewed on the lever 29:. The swinging or oscillating motion of thelever 29 is derived, by way of a roller lever not-shown, from a cam 5|(Fig. 5) fastened to the main shaft 1.

Attached to the hooked needle 7 an auxiliary needle 8 (Fig. l) iscoordinated as thread stripper, lagging behind with respect to the upanddown-motion of the hooked needle, said needle 8 being driven, by way ofthe eccentric rod to and the lever H, by the eccentric 9 fixed on themain shaft i, and lagging by 90 in res ect to the crank 2 (Figs. 1, 2and 4). connected for rotation to the lever l2 by means of a shaft [3awhose bearing 53 is fastened to a bar I8, arranged in the head, so thatit can be lifted and lowered, whereby said lever 52 engages-by way of alink Ill (Fig. 2)a block i5 tightly screwed on to the bar N5 of theauxiliary needle. A guide l9, fastened to the auxiliary needle bar 16,secures same against rotation by being slidingly guided along flat faces(Fig. 3) of the bar 18, carrying the hearing it of the auxiliary needlelever. At the lower end of the auxiliary needle bar 15, the holder I!for that needle is fixed, an oblique arm bringing it closelyto thehooked needle 7. The auxiliary needle Rhas. a cylindrical fastener,tapers down conically towards the point, and is unilaterally-flatteneddown to same.

Besides the auxiliary needle 3, the holder ll carries a small guideplate 37 (Fig. 1), whereby the needle-with its flattened part-snuglynestles to the front of the hooked needle I, the plate 31 resting on itsrear side, and preventing the hooked needle I from bending during thefeed of the material 50.

The bar [8, guiding the auxiliary needle, is by a screw 2! (Figs. 2 and4)coupled to the presser foot bar 20, which permits of adjusting, atvarious levels, both the bar 18 guiding the auxiliary needle, and thebearing it for the auxiliary needle lever, fastened to same inconformity with the level of the presser foot 35 corresponding to thethickness of the material to be sewn. For this reason, the enteringdepth of the auxiliary needle 8 is operatively adapted to the thicknessof the material.

The lever H is I On the upper side of the nut Zia of the screw 2! (Fig.2), coupling the two bars I8 and 20, the free end of a robust and sturdyplate spring 22 is located whose other end is held fast by the head,said spring pressing the presser foot downwards on the material 50. Forlifting the presser foot 35 a lever 33, operatable by means of the kneethrough a system of rods, not shown, and the usual hand lever 34 areused, whereby the presser foot bar 28 is lifted against the action ofthe plate spring 22 by way of the bearing N3 of the auxiliary needlelever, the guide bar i8, and the coupling screw 2!.

The material feed dog 24 passes in the manner known through a recess ofthe needle plate 23.

The mode of operation of the new machine is best explained withreference to the Figs. 5-11.

Fig. 6 shows the two needles 6, l at the beginning of the retrogressionfrom their lowest level. The point of the thread transmitter 25 rotatingin the direction of the arrow whose position corresponds approximatelyto the position A of the cam 51 (Fig. 5) catches the thread loopproduced at the eye-needle 6. In the meantime the auxiliary needle 8 andthe guide plate 31 will have attained their lowest level.

While the cam 51 (Fig. 5) rotates in the direction of the arrow, and theneedles 6 and 7 continue to ascend, the thread transmitter 25 has aftera rotation of about 180-laid the threadloop a, which it has caught,about the hooked needle 1 (Fig. 7). After an additional rotation of theearn 5! through the angle AOB whereby the cam follower 52, guided in thecontrol slot ofsaid cam, attains its outermost position to the left, thetransmitter 25 reaches its limit posi tion of 360 which, is keptunaltered during the further rotation of the cam 5! through the angleBOC.

The thread loop a released by the thread transmitter 25 ispulled up bythe hooked needle- I through the material 50, and through the lastthread loop a, formed during the preceding stitch of the needle and, tothat moment, kept fast'by the auxiliary needle 8 (Fig. 8) whereby-out ofthe thread loop a-on.the lower side of the material St? the double seamwebs d are formed. The auxiliary needle 8, ascending with the hookedneedle 1, but lagging behind same, thencovers the hook opening so as toprecludethe former thread loop being. caught a second time.

Fig.9 shows the two needles 6, i on their. 1??? turn-stroke after havingreached. their topmost position, whilstv the auxiliary needle. 8.sti1l;oc;- L cupies its topmost position. In the meantime the materialfeed. dog 24 has advanced the ina-' terial by onestitch length, andprepared it' forthe subsequent stitch. It results therefrom. that thethread loop a'is tensioned to the-lengthof the chain-stich a as desired,and that also the thread guided by the eye-needle 6 is tensioned forforming the quilting-stitch-like junction-stitch c. I

In the meantime the thread transmitterl'i terminates its return-rotationby 360 corre-' sponding to the motion of the cam 5| through the angleCOD. During the further rotation of the cam 5| through the angle DOAback into the initial position its roll 52 remains in itsout ermostposition to the right, correspondingto the position of the threadtransmitter 25 in the Figs. 9 and 10. When the material feed dog 24 hascompleted the advance of the material 50, and when the needles 6-, 7have again'begun to" stitch I into 1 same: whereby the auxiliary needlefagsbehind releasing the hooked needle opening, the thread loop a,previously drawn up, is stripped from the hooked needle 1, and is passedin the middle by the two needles 6 and I, so as to complete the newchain-stitch loop a and the quiltingstitch-like junction-stitch c.

When the needles 6 and l have left behind their lowest position, and theauxiliary needle 8 has again penetrated into the material 50 to be sewn,holding fast thereby the new chain-stitch loop a, the initial positionaccording to Fig. 6 is again attained.

. The second, diagrammatically illustrated mode of execution of themachine according to Fig. 11 is adapted to produce a two-row seam bymeans of only one upper thread, said seam being characterized by thechain-stitches a, band the quilting-stitch-like junction-stitches beingjuxtaposed in rows whilst the connecting seam websd are arrangedtransversely. In contradistinction to the first embodiment the needles6, I are arranged in a plane vertical to the feeding direction of thematerial 50 so that-looked at in the direction of transport-the hook ofthe needle I is located in front whilst the thread eye at the eye-needle6 occupies a longitudinal position. The oscillating position of thethread transmitter 25, again provided below the needle plate 23, andhaving its vertical axis laterally displaced in respect to the axes ofthe needles 6, I, must be adapted to the new needle plane for whichpurpose the said transmitter must be fastened on its shaft in a positionturned by 90 in respect to the former position. For the rest theformation of the stitches is effected as illustrated in the Figs. -10.

By way of a constructive reversal of the machine, particularly adaptedfor border quilting, the needles 6, 7 can be arranged in the bottom partof the head e. g. the arm so as to make them enter into the material 50from below, in which case the thread transmitter 25, the auxiliaryneedle 8 including its driving parts, and the feeding device arearranged in the top part of the head.

What I claim is:

1. A sewing machine for making a one-thread machine seam consisting ofchain stitches and quilting-stitch-like junction stitches on theentering side of the material connected on the exit side byquilting-stitch-like double seam webs, said machine comprising a mainshaft, an eye needle, a hooked needle having a hook which is open at thefront when viewed in the direction of material feed, means operativelyconnecting said eye needle and hooked needle to the main shaft to movesaid needles in synchronism through the material, a thread transmitteroperably connected to means fixed to a stationary machine part, forguiding said thread transmitter on the needle exit side of the materialacross the paths of said two needles, an auxiliary needle lying closelyalong the front side of the hooked needle, first timing meansoperatively connecting said thread transmitter to said main shaft tomove said thread transmitter in a timed relationship relative to themovement of said eye needle and hooked needle, whereby the threadtransmitter is adapted to present a thread supplied by the eye needle asa loop to the hooked needle during the return movement thereof, andsecond timing means operatively connecting said auxiliary needle to saidmain shaft to move the auxiliary needle with a QO-deg. lag behind saideye needle T and hooked needle along the 1 front side of the hookedneedle. "-1

2. A sewing machine as .set forth in claim 1, which comprises a firstrod insaid means operatively connecting said eye needle and hookedneedle to said main shaft, a second rod opera and a guide plate, saidholder being'fixed-to the second rod, the auxiliary needle lying withits flat side against the front side-of the hooked needle and the'guideplate bearing against the rearside ofthehooked needle.- A sewing'machineas set forth in claim 2, which comprises connecting 'means-'operative'ly connecting said main shaft'with'saidfirst rod in saidmeans operatively connecting said eye needle and hooked needle to saidmain shaft, and in which said second timing means comprise an eccentricmounted on said main shaft with a QO-deg. lag behind said connectingmeans, and a lever system operatively connecting said eccentric to saidsecond rod.

4. A sewing machine as set forth in claim 2, which comprises connectingmeans operatively connecting said main shaft with said first rod in saidmeans operatively connecting said eye needle and hooked needle to saidmain shaft, and in which said second timing means comprise an eccentricmounted on said main shaft with a deg. lag behind said connecting means,a lever system operatively connecting said eccentric to said second rod,a shaft, a bearing for said shaft, a guide part fixed to said secondrod, and a guide rocl carrying said bearing and engaging with said guidepart to guide it along a straight line, said lever system comprising aneccentric rod operatively connected to said eccentric, an angle leverhaving two arms fixedly connected to said shaft, and a linkarticulatedly connecting one of said arms to said second rod, the otherof said arms being connected to said eccentric rod.

5. A sewing machine as comprising a presser the auxiliary needle.

6. A sewing machine as set forth in claim 5, in which said second timingmeans comprise lever means operatively connected to said main shaft andsaid auxiliary needle, a shaft carrying said lever means, a bearing forsaid shaft, a movable carrier for said bearing, and which comprises apresser foot carrier positively connected with saidv presser foot andsaid carrier for said bearing, and a spring for loading said presserfoot.

'7. A sewing machine as set forth in claim 1, which comprises anoscillating looper constituting said thread transmitter, and in whichsaid first timing means comprise a cam on said main shaft, said camhaving a closed guide slot, and a transmitting member operativelyconnected with said oscillating looper and engaging with said guideslot, said guide slot having a steeper part for the guidance of thelooper during its effective movement and a flatter part for the guidanceof the looper during its return oscillation, said slot parts beingconnected by conset forth in claim 1, foot positively connected toaesenox material feed, being arranged one behind the other, the hookedneedle with a forwardly directed hook being in front and the eye needlewith a transversely positioned thread eye being behind.

'9. A sewing machine as set forth in claim 7, in which said means forguiding the thread transmitter comprise pivot means about whichsaid-looper is pivotally movable and which are fixed to a stationarymachine part, the axis of said pivot means being laterally spaced by the81 radius: of the looper oscillation: from the of the eye needle and thehooked needle, said two needles being arranged in a plane pea'pe11--dicular to the direction of material feed, the hook of the hooked needlewhen viewed. in the direction of material feed, being directed:forwardly and the eye of the eye needle being posi' tionecllongitudinally.

FRANZ MIKOLAS.

References Cited in the file of this patent UNITED STATES PATENTS-Number Name Date 1,095,199 Fink May 5, 1914 1,934,328 Rubel Nov. '7,1933 2,118,077 Fink May 24, 1938' 2,390,126 Schifter Dec. 4, 19452,409,149 Pikul Oct. 8', 1946' 2,411,977 Pikul Dec; 3, 1946 2,491,457Sigoda Dec. 13, 1949'

